Learning Curve for Transanal Total Mesorectal Excision for Low Rectal Malignancy

Abstract

BACKGROUND: Although transanal total mesorectal excision (TaTME) is a promising treatment for low rectal cancer, it is considered technically demanding, and the number of cases required to become proficient in TaTME remains unknown. The purpose of this study was to assess the TaTME learning curve based on the total mesorectal excision completion time. STUDY DESIGN: This retrospective analysis comprised 128 individuals who received TaTME between September 2016 and December 2021. The cumulative sum method was used to generate the learning curve. The duration of the procedure from the beginning to the end of the circumferential rendezvous was used to define the total mesorectal excision completion time. RESULTS: The learning curve consists of 3 phases: phase I (learning phase: cases 1 to 38), phase II (consolidation phase: cases 39 to 70), and phase III (maturing phase: cases 71 to 128). As the phases varied, both the overall operative time and total mesorectal excision completion time decreased considerably. Through the 3 phases of TaTME, intraoperative adverse events decreased, and in phase III, none occurred. Only 1 instance of local recurrence occurred during phase III, and none occurred during phase I or II. CONCLUSIONS: After 70 operations, the surgeon could join the mastery phase of TaTME based on the total mesorectal excision completion time. After the mastering phase began, there were no intraoperative negative occurrences. From the beginning, the oncological safety could be guaranteed.

Local Recurrence of Rectal Cancer After Transanal Total Mesorectal Excision and Risk Factors: A Nationwide Multicenter Cohort Study in Japan

“…Similarly, we did not find the number of procedures performed by the individual surgeon to be a risk factor for LR; the median number in our study was 20 (IQR: 6, 41), which appears insufficient in view of previous research suggesting that the learning curve requires at least 40 cases. 33 – 35 However, according to our data, limited experience is not in itself associated with a poor oncological outcome as long as the procedure is performed correctly and in appropriately selected patients. Further evidence in support of this view is our finding in univariate analysis that hospital volume was not a significant risk factor for LR (hazard ratio 1.00, 95% CI: 0.97–1.02).…”